A while ago I had some email correspondence with someone who said they taught a particular martial art.
When I enquired where they had learned it the reply was ....from a DVD.
Now I don't have a problem with people learning from a DVD if there is no teacher available, or then practising the material with some friends.
But to make a public statement you are teaching that martial art is ,in my personal opinion, dishonest and misleading.
The teaching, correction and feedback from an instructor in person is essential.
Always check where and with whom your instructor studied.
At the end of the day, it is up to you, of course. But let the Buyer Beware!